[miele] Temperature channel improvements: UoM, categories and descriptions (#11329)

* Improvements for temperature channels

Fixes #11317

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Added jlaur as miele binding maintainer

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Fix spinning speed for washing machines

Fixes #11317

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Added time as category for DateTime-related channels

Fixes #11317

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Elapsed/remaining time channels are no longer marked as advanced.

Fixes #11317

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Fixed type for temperature item examples.

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Document all states (cross-appliance).

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Improved error handling for getTemperatureState

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Split current/target temperature into two channel types for label reuse

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Fix possible NullPointerException

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Distinguish between oven program temperatures

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

* Mark oven program temperature 1 and 2 as advanced.

Fixes #11317

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

CODEOWNERS

@@ -168,7 +168,7 @@
 /bundles/org.openhab.binding.meteoalerte/ @clinique
 /bundles/org.openhab.binding.meteoblue/ @9037568
 /bundles/org.openhab.binding.meteostick/ @cdjackson
-/bundles/org.openhab.binding.miele/ @kgoderis
+/bundles/org.openhab.binding.miele/ @kgoderis @jlaur
 /bundles/org.openhab.binding.mielecloud/ @BjoernLange
 /bundles/org.openhab.binding.mihome/ @pboos
 /bundles/org.openhab.binding.miio/ @marcelrv